I'm curious what people think would happen if a pump like a Perry V30 was used. http://www.perrypumps.com/prod02.htm

I have a plane setup (not yet flown) where the tank can be placed in the usual position. Alternatively, I can (and will) put it back over the CG and use the V30 pump. But when back over the CG the bottom of the tank is in line with the carburetor.

When placed over the CG, the tank is higher than normal, but with the pump I expect that I will be able to tune the engine with the tank full, then as it drains (static pressure drops) the pump will make up the difference. Same goes for when the plane flips upside down.

Anyone ever tried something like this?

The plane happens to be a Great Planes Tracer. You can squeeze the tank in under the canopy. That's just a tad in front of the CG. The pump fits nicely between the engine and firewall.
The engine mounted at roughly 45 degrees - that raises the carb just enough to line up with the bottom of the tank.